This invention relates to apparatus for correcting the distortion of the attenuation course of a non-loaded, e.g., by coil, low frequency cable, in which the cable is connected to a transmitter and to the receiver, and in which a base band signal is transmitted.
In transmission systems in which a base band signal is transmitted via a cable link from a transmitter to a receiver, as is known, the receiver contains a distortion correcter with the aid of which the attenuation characteristic of the cable is manually adjusted in order to transmit the base band signal over as long as possible distances. Distortion correcters of this kind usually comprise an amplifier which contains an RC element with which it is possible to influence the gain of the amplifier. It is known to use the series combination of a capacitor and a potentiometer as the RC element, in which case the distortion correction is effected by manual adjustment of the potentiometer resistor. This manual adjustment of the distortion correction is disadvantageous since in the production of the receivers it is not possible to predict which cable must be connected to the receiver in the operating state, so that the distortion correction of the attenuation characteristic need only be effected before the receiver is set in operation.
An object of the invention is to provide apparatus for the automatic distortion correction of the attenuation characteristic of a low frequency cable.